Once a character is a Best Friend to Ella, she sends the character a letter in the mailbox, along with a Tree Seed Pack .

From: EllaSubject: A Letter From Ella

Hello <player>,

I hope that this letter finds you well.

I am so very glad that we are best friends now, so I got you a few gifts. I didn't want you to be lonely on your farm, so I'm giving you my most favorite cat - Luna. Please take good care of her. You'll find her on your farm the next time you visit.

These trees have brought me great joy in the past, and I hope they bring you the same happiness.